In a general wire harness for a vehicle, a so-called twisted electric wire where a resin serving as an insulation cover is extruded onto an outer periphery of a conductor consisting of a twisted wire has been used. When arranging the wire harness in a vehicle, it is necessary to adopt a liquid-proof measure to prevent water or oil from being infiltrated into the electric wire through a gap between the conductor of the electric wire configuring the wire harness and the insulation cover, depending on positions at which the wire harness is arranged. When the water or oil is infiltrated into the electric wire, the insulation cover may be deteriorated or the other adverse influence may be caused.
As an example of the conventional liquid-proof measure, a waterproof structure as shown in FIG. 4 is known. In FIG. 4, a reference numeral 20 indicates a covered electric wire, and an insulation cover 22 is provided on an outer periphery of a conductor 21 consisting of a twisted wire by extrusion molding. A connection terminal 40 is adhered to a terminal of the covered electric wire 20. The connection terminal 40 is connected to an exposed part of the conductor 21 at the terminal of the covered electric wire 20 by a conductor crimping part 41 that is provided at a rear end of the connection terminal 40, and a rear half part other than a front end 42 is accommodated in an internal space 38 of an inner housing 31 made of insulating resin, including the conductor crimping part 41 connected to the terminal of the covered electric wire 20. The front end 42 of the connection terminal 40 protrudes to the outside more than a front end of the inner housing 31. The other terminal and the like are connected to the front end 42. Also, the connection terminal 40 is engaged at a fixed position by an engaging member 35 that is provided to the inner housing 31. In the meantime, an outer side of the inner housing 31 is covered with an outer shell 32.
Also, the inner housing 31 is provided at its front part and rear part with a first seal member 28 and a second seal member 25, respectively. The first seal member 28 provided at the front part is arranged in a terminal insertion-through hole 36 of the inner housing 31 and is in close contact with an inner wall of the terminal insertion-through hole 36 and a longitudinally central part 43 of the connection terminal 40, thereby sealing a gap between the connection terminal 40 and the inner housing 31. Also, the second seal member 25 provided at the rear part is accommodated in a rear part opening 37 of the inner housing 31 and an outer lip 26 is in close contact with an inner wall of the rear part opening 37 of the inner housing 31 and an inner lip 27 is closely contacted to an outer periphery of the insulation cover 22 of the covered electric wire 20, thereby sealing between the insulation cover 22 of the covered electric wire 20 and the inner housing 31. In the meantime, the outer lip 26 and the inner lip 27 of the second seal member 25 are provided with adhesive force as a seal pressing member 33 is pressed.
In this way, the internal space 38 of the inner housing 31 is sealed by the first seal member 28 and the second seal member 25. Thereby, it is possible to block the liquid that is about to be infiltrated from the front end of the inner housing 31, as shown with an arrow A1, and to block the liquid that is about to be infiltrated from the rear end of the inner housing 31, as shown with an arrow A2. Accordingly, it is possible to prevent the liquid from being infiltrated into the gap between the conductor 21 and the insulation cover 22 from the exposed part of the conductor 21 at the terminal of the covered electric wire 20, as shown with an arrow A3.
In the meantime, the above waterproof structure is well known in Patent Literature 1 and the like.